The subject matter disclosed herein relates generally to magnetic resonance imaging (MRI) systems, and more particularly to a method of performing accelerated Diffusion Spectrum Imaging (DSI) using an MRI system.
DSI is an imaging technique to generate diffusion information that may be utilized in the clinical evaluation of various diseases, for example, traumatic brain injuries and/or multiple sclerosis. In DSI, the information is encoded in both q-space or diffusion space and image space. The q-space information may then be used to characterize the diffusion properties of water molecules. More specifically, by applying a series of diffusion encoding gradient pulses in multiple directions and strengths, a three-dimensional characterization of the water diffusion process may be generated at each spatial location (image voxel). The MR signal in q-space is generally related to the water displacement probability density function at a fixed echo time by the Fourier transform. The diffusion information encoded in q-space may be separated into both angular and radial components. The angular component reflects the underlying tissue anisotropy, whereas the radial component provides information about the eventual geometric restrictions in the diffusion process.
Conventional DSI techniques provide acceptable information for the diffusion properties of water in the brain or other organs. However, the high dimensionality of DSI (3D in spatial domain and 3D in q-space) requires the patient to be scanned for an extended period of time, which substantially limits the effectiveness of the conventional DSI technique when utilized in vivo.